Mini Roundabouts - Keep getting beeped at

I have been driving for just over a year, and the two scenarios I have been beeped at by another car have both been on mini roundabouts, so I presume I'm doing something wrong and was wondering if I could have some advice.

Both situations are as follows. I have a car to my right at the mini roundabout, they haven't yet "joined" the mini roundabout but they are stopped at the junction, their way is clear, no indicators on. As they are to my right they have right-of-way so I wait. They are just sat there at the junction not indicating, not doing anything just sitting there. After a few seconds of this I get beeped at for not going, and then I move onto the mini roundabout to go straight ahead, therefore pulling out in front of a car which has priority over me, hoping they won't decide that now is the time they will move onto the mini roundabout.

I get that it's annoying to be hesitant at a roundabout and I know that's why they beeped me, and yeah it got to the point where I just had to go despite the car to my right. But is there something I'm missing?

if there's a car waiting to your right they have priority, but if another car is driving past it from their right, then that's a chance for you to drive on. I'm not sure if you currently learning or have already passed, if you're learning then your instructor should be explaining why they beeped. If you've already passed, it's probably just best to stick to the rules and give priority to the right despite the beeps, i think most people don't usually follow the rules of a roundabout once they've passed, you could probably get away with it too but it could likely result in an accident.

Mini roundabouts, especially three-way ones, are notoriously prone to stand-off situations. Just go cautiously (keeping eye to right) if you come across it and there is no movement. Beeps from cars behind in such situations should be ignored - it is you that could crash, not them.

Thank you. Yeah it was a three way one, the junction to my right had a car waiting but his way was completely clear to go, so if he had been turning right he would have crossed my path. Surely it is that driver in the wrong and not me, as you should not sit at a junction with no signal on and no other signalling to other drivers (he didn't flash for me to go or any indication of what was going on in his mind).

if there's a car waiting to your right they have priority, ...............

Utter nonsense.
"Give way to traffic approaching from the right".
A car waiting to enter is not approaching from anywhere.

.......... If you approach a mini roundabout with someone to your right, you must let them go first..

Furthermore, the HC clearly states give way to traffic already on the roundabout, OR approaching from the right.

Who says "you must let them go first"
it does not say any such thing.

You're absolutely clueless.

Rule 185

There is a clear distinction between traffic already on the roundabout, and those approaching.

It is fine quoting the highway code but you obviously do not understand it.
Going back to your previous statements. Where does it say " If you approach a mini roundabout with someone to your right, you must let them go first.."
And where is your quote that "Furthermore, the HC clearly states give way to traffic already on the roundabout, OR approaching from the right." Neither of your quotes exist in the HC.
You are clearly misunderstanding what is meant by "approaching from the right".

Are you thick?

There are two completely separate statements, one that states give way to traffic on the roundabout, and another for traffic approaching. It's a very clear distinction.

As previously mentioned, priority to the right is an overarching principle of driving in the UK, amongst other countries in the Vienna Convention.

Ehem, no......

What do you propose is to happen if you come to the roundabout then? No one moves? What a pathetic argument.

Traffic police and insurance companies all agree that on a mini-roundabout (where there is not enough room for anyone to already be travelling around the roundabout), traffic to the right waiting to join has priority. This is a commonly understood rule of the road, whether it's explicitly written down or not

This is pub lawyer talk. They do not agree any such thing, and I can assure you that no "commonly understood rule of the road, whether it's explicitly written down or not" has priority over the Highways Act.
At a roundabout, traffic on the roundabout has priority. It is going clockwise so approaching from the right.
Traffic approaching the roundabout is not on the junction and does not have priority over any other traffic approaching the junction

Utter nonsense.
"Give way to traffic approaching from the right".
A car waiting to enter is not approaching from anywhere.